Purpose: Recent research indicates that physiotherapy interventions, such as exercise and manual therapy, may be effective in decreasing the frequency of side effects linked with breast cancer treatment, including fatigue, pain, nausea, and decreased quality of life. This systematic review aims to determine the efficacy of exercise therapy in reducing shoulder pain related to breast cancer treatment and to identify outcome measures that can be used to assess shoulder pain in this population. Methods: A systematic review of the current literature was conducted using portals such as the Physiotherapy Evidence Database (PEDro), the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, Ovid MEDLINE (1996 to April 2011), and Allied and Complementary Medicine (AMED) (1985 to April 2011). Databases were searched for relevant studies published up to April 2011. Participants in relevant studies were adults (>= 18 years of age) with a primary diagnosis of breast cancer at any point during the treatment of their disease. Results: Six articles were independently appraised by two blinded reviewers. Six studies met the inclusion criteria, each analyzing different types of exercise-shoulder/arm/ scapular strengthening/stabilization, postural exercises, general exercises and conditioning, shoulder range-of-motion exercises, and lymphedema exercises-with respect to their efficacy in reducing shoulder pain related to breast cancer treatment. Conclusions: Results suggest that exercise targeting shoulder pain related to breast cancer treatment may be effective. However, definitive conclusions cannot be drawn due to the lack of methodological quality and homogeneity of the studies included. Clinicians should use valid outcome measures, such as the visual analogue scale and brief pain inventory, to evaluate the effectiveness of this treatment.